We investigated that the CARS signals generated from resonant or nonresonant contributions can be selectively suppressed by phase-controlled nonlinear interferometry. To control the phase of the CARS signal over a broad spectral range, a home-made phase shifting unit was used, whose thickness was automatically controlled as the wavelength of Stokes beam scaned. Using this technique, we recovered the Q-branch resonance lines of carbon monoxide and HC1 which had been distorted and buried by the nonresonant and resonant signal of propane respectively. All the spectrum measured have been normalized by reference signal which had no resonance lines over the spectral range of interest.